The present invention relates to rolls of the type used in paper machines and in particular to methods for manufacturing such rolls.
As is well known, rolls of this type may include an inner roll body which is provided at an exterior surface with a covering in the form of an elongated strip which may be helically wound onto the roll body so as to surround the latter with a plurality of strip portions each of which extends circumferentially around the roll body and which are situated one next to the other axially along the roll body. The strip may be of a suitable profile so as to provide the covering for the roll with an exterior grooved surface of any desired characteristics, although the strip also may have a uniform thickness so that an ungrooved smooth-surfaced covering is provided for the roll. The roll body may be a solid body or it may be a hollow sleeve.
The elongated strip which is used to cover the roll body is preferably made of a corrosion-resistant material such as stainless steel, for example. The profile of the strip may be uniform so that the entire exterior surface of the roll provided by the outer surface of the strip may be either continuous or grooved, or the profile may be such that any desired combination of grooved and ungrooved exterior surface portions may be provided at the exterior of the finished roll.
Roll coverings in the form of a continuous strip wound onto a roll body or the equivalent thereof and intended for use in paper machines are known. For example reference may be made in this connection to U.S. Pat. No. 3,718,959, and also reference may be made to application Ser. No. 620,229 filed Oct. 6, 1975. Thus, roll-covering methods as disclosed in the above patent and application may also be utilized in the present application.
One of the problems encountered with rolls of the above type resides in the reliability with which the successive strip portions, each of which circumferentially surrounds the roll body, are fixed one to the next so that they will not tend to move apart from each other. Various expedients are known for the purpose of reliably fixing one circumferential strip portion to the next circumferential strip portion in a highly reliable manner which will serve to prevent these strip portions from moving apart from each other at least axially, and also which will prevent the strip portions from moving radially outwardly away from the inner roll body on which the strip portions are initially located.
Up to the present time reliance has been made on expedients such as providing the strip with a profile according to which one side surface of the strip has a groove and the opposed side surface thereof has a projection so that when such a strip is wound onto a roll body the projection of one turn is received in the groove of an adjoining turn, and thus through expedients of this type it has been attempted to provide a reliable connection of the successive strip portions to each other. Procedures of this latter type may be used in the present invention also.